Immunization with a streptococcal multiple-epitope recombinant protein protects mice against invasive group A streptococcal infection

PLoS One. 2017 Mar 29;12(3):e0174464. doi: 10.1371/journal.pone.0174464. eCollection 2017.

Abstract

Streptococcus pyogenes (group A Streptococcus; GAS) causes clinical diseases, including pharyngitis, scarlet fever, impetigo, necrotizing fasciitis and streptococcal toxic shock syndrome. A number of group A streptococcus vaccine candidates have been developed, but only one 26-valent recombinant M protein vaccine has entered clinical trials. Differing from the design of a 26-valent recombinant M protein vaccine, we provide here a vaccination using the polyvalence epitope recombinant FSBM protein (rFSBM), which contains four different epitopes, including the fibronectin-binding repeats domain of streptococcal fibronectin binding protein Sfb1, the C-terminal immunogenic segment of streptolysin S, the C3-binding motif of streptococcal pyrogenic exotoxin B, and the C-terminal conserved segment of M protein. Vaccination with the rFSBM protein successfully prevented mortality and skin lesions caused by several emm strains of GAS infection. Anti-FSBM antibodies collected from the rFSBM-immunized mice were able to opsonize at least six emm strains and can neutralize the hemolytic activity of streptolysin S. Furthermore, the internalization of GAS into nonphagocytic cells is also reduced by anti-FSBM serum. These findings suggest that rFSBM can be applied as a vaccine candidate to prevent different emm strains of GAS infection.

MeSH terms

  • Animals
  • Bacterial Proteins / biosynthesis
  • Bacterial Proteins / genetics
  • Bacterial Proteins / immunology
  • Base Sequence
  • Cysteine Endopeptidases / biosynthesis
  • Cysteine Endopeptidases / genetics
  • Cysteine Endopeptidases / immunology
  • Epitopes
  • Escherichia coli
  • Female
  • Mice, Inbred BALB C
  • Recombinant Proteins / biosynthesis
  • Recombinant Proteins / genetics
  • Recombinant Proteins / immunology
  • Streptococcal Infections / immunology
  • Streptococcal Infections / microbiology
  • Streptococcal Infections / prevention & control*
  • Streptococcal Vaccines / administration & dosage*
  • Streptococcal Vaccines / immunology
  • Streptococcus pyogenes / immunology*
  • Vaccination*
  • Vaccine Potency
  • Vaccines, Synthetic / administration & dosage*
  • Vaccines, Synthetic / immunology

Substances

  • Bacterial Proteins
  • Epitopes
  • Recombinant Proteins
  • Streptococcal Vaccines
  • Vaccines, Synthetic
  • Cysteine Endopeptidases
  • streptopain

Grants and funding

This work was supported by grants MOST104-2320-B-214-004, MOST105-2320-B-006-011, and MOST 105-2320-B-214-004 from the Ministry of Science and Technology, and ISU103-04-05A from I-Shou University, Taiwan. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.